Continued: Buttermilk: Not just for grandma anymore

“This produced sweet, unfermented buttermilk, which could be sold as such or cultured with lactic bacteria to develop the traditional flavor and consistency,” he writes.

After World War II, an imitation “cultured buttermilk” was invented, he writes, made from ordinary skim milk — the same pasteurized, homogenized milk you buy at the store — and fermented until acid and thick.

What’s the difference?

“True buttermilk is less acid, subtler and more complex in flavor,” McGee writes. And it’s rich in valuable emulsifiers like lecithin.

You’d have to churn your own butter to find out for yourself. But what you can find is powdered buttermilk made from true buttermilk.

For 30 years, Saco Foods in Middleton, Wis., has been purchasing buttermilk from butter manufacturers and turning it into powder. Because it’s less processed (the buttermilk does need to be pasteurized), the company says Saco’s nationally distributed Buttermilk Blend retains the natural emulsifiers that yield those fine-textured foods.

“Fluid buttermilk, too, will have an effect [on foods], different from straight milk,” said Saco general manager Amy Verheyden. “But if you make the same recipe with fluid buttermilk and then with powdered, there really is a difference.”

To use the powder in baking or other batters, just mix it in with the other dry ingredients, then add the appropriate amount of water to the liquid ingredients. (Four tablespoons of powder plus 1 cup water equals 1 cup buttermilk.)

However, you’ll want to use fluid buttermilk for cold salads, dressings and the like, “anything that relies on the thickness of the buttermilk,” Verheyden said. “Liquid buttermilk contains live cultures, which makes it thick. If you reconstitute powdered buttermilk, you won’t get that thickness.”

Once opened, the powder should be stored in the refrigerator, where it will keep for several years.

Buttermilk tips

• You can substitute buttermilk for regular milk in just about any baking recipe, cup for cup — but some experts advise making sure the recipe includes at least ½ teaspoon baking soda per cup of buttermilk. If the recipe calls for only baking powder, replace enough of the powder with baking soda to meet this requirement.

• A little buttermilk substituted for some of the liquid in the batter of a baked good will prevent the blue discoloration you often get around cherries and berries such as blueberries, raspberries, blackberries and strawberries.

• Always shake fluid buttermilk before using.

• Because buttermilk is cultured, like yogurt, it will keep longer in the refrigerator than regular milk. However, it does not freeze well.

• Because buttermilk is cultured and fermented, it curdles easily when heated, more so than milk or cream. Avoid stirring it directly into very hot dishes, such as hot soups.